Chest for piston-valves.



L. L. DAWSON & J. L. ROACH.

CHEST FOR PISTON VALVES.

APPLICATION FILED SEPT. 27. 1915.

LANCE L. DAWSONAND JOHN L. ROACH. 0F GHILDRESS, TS.

crinsr non PISTON-VALVES.

Specification of Letters Patent.

Patented May 23, 1916.

Application filed September 27, 1915. Serial No. 52.930.

and constructed with a view to being expeditiously and easily applied to the piston cylinder of a locomotive in th place of a removed slide-valve chest, whereby, without loss of the cylinder, the locomotive may be adapted to'iuse superheated steam and high pressures.

Other advantageous features of the invention will be fully understood from the following description and claim when the same road in connection with the drawings, accompanying and forming part of this specification, in which:

" Figure 1 isa view,'partly in end elevation and partly in transverse section, showing our novel chest with the bushing in position and the head. removed. Fig. 2 is a view. partly in side elevation and partly in longitudinal-central section, with the heads omitted. Fig. 3 is a fragmentary view showing the internal construction around the peephole in the chest and the offset in the web to accommodate said hole. Fig. 4; is a transverse section through the recesses 17.

Similar numerals of reference designate corresponding parts in all views of the draw Will ings.

The chest 1 is made of cast-iron, is flat-at its underside, is provided throughout its length with a bore 10 for the reception of a bushing 9, Figs. 1 and 2, and is formed at its ends with circular portions 11 in the faces of which are apertures 12-, Fig. 1, designed to receive the threaded studs (not shown) through the medium of which the heads (also not shown) arefixed to the ends of the chest. The bushing 9 extends the full .length of the chest 1 and is designed to tice steam is present at all times in the end ports, and passes through the end slots of the bushing to the interior thereof. It is then admitted alternately into the ends of the cylinder by the action of the reciprocating valve (not shown) uncovering first one and then the other of the admission ports. At its base the chest 1' is provided with a flange 2, and in said flange are apertures 13 for the passage of studs 14 throughwhich the chest is bolted downgon the old seat on the piston cylinder; the apertures 13 being by preference so arranged that the studs 14- will occupy the old holes in the said seat on the cylinder. The plan of the bottom of chest 1 conforms to the shape of the slidevalvesteam chest it is designed to replace, and in said bottom are openings 6 that register with the port openings in the old seat on the piston cylinder. Around the openings 6 are grooves to hold copper-wire gaskets 8. designed to make a steam-tight joint when the chest 1 is tightened down by the studs l-i.

Interiorly the chest 1 is provided with passages 15, one in vertical alineinent with each opening 6, so that in effect the said openings 6 are prolonged or led up around the bushing 9 which is of standard type and provided with openingscorresponding to the openings 6 and the passages 15. Formed in the chest 1 at 5 is a peep-hole, designed to be normally closed by a threaded plug (not shown). Said peep-hole is provided in order that the position of the valve can be seen from the outside of the chest. The interior constiuci tion of the peep-hole is shown in Fig. 3. When desired, the peep-hole may be duplisated at the same side of the chest and at, the same dlstance from the transverse center Exterior cavities 17 are cast in the chest 1 adjacent to the ends thereof to receive the heads of certain studs with a view to enabling the overhanging outside of the cylindrical portion of the chest to clear said heads. It will also be noted that the chest is provided adjacent to its ends with interior cavities 17 (see dotted lines Fig. 1) designed to receive the heads of certain studs in such manner that the bushing 9 clears said heads. to the cavities 17 and 17 are, like the apertures 13, so arranged, by preference, that studs placed therein will occupy old holes in The apertures complementary the seat on the cylinder. In its top the chest.

a smooth surface for-painting or other fin- "ishlng.

It will be gathered from the foregoing that the valve chamber of our novel chest is of very large diameter, as is desirable; also, that the chest does not entail the employment of a separate, inner valve chamber and the appurtenances thereof which manifestly renders it' inexpensive and easy to repair. It will further be understood that after a slide-valve chest is removed from a locomotive cylinder, it is simply necessary to plane down the valve seat and apply and connect our novel chest, after which the valve-operating mechanism that was employed to actuate the old slide-valve can be used to move the piston valve in. bushing 9. In this connection it is to be understood that the piston valve per se is of the ordinary-well-known construction, and that its stem operates the valve at the center thereof in the usual manner; said stem being carried'throngh a suitable stuffing box in one of the heads.

Having described our invention, what we claim and desire to secure by Letters-Patent, 1s:

Means for the purpose described, comprising a cast-metal piston-valve chest having ends constructed and arranged for the connection of heads, and a bore extending between said ends, and also having a flatarranged in the bore of the chest and con structed and arranged for the reception and operation of a piston-valve.

-In testimony whereof we have hereunto set our hands in presence of two subscribing witnesses,

LANCE L. DAWSON. JOHN L. ROACH.

Witnesses:

D VE R. WILLIAMS, F. S. HARDIN. 

